Tim Tebow: I'm NOT Speaking at RNC ... 'Just a Rumor'

Sorry, Trump ... Tim Tebow will NOT be joining Dana White as a celebrity guest speaker at the Republican National Convention next week ... calling the whole thing a silly "rumor."

FYI, Tebow's name was on a roster of RNC speakers obtained by the New York Times -- a roster that included Dana White (who confirmed he is speaking) but the QB made a video saying the whole thing is BS.

"It's amazing how fast rumors fly ... and that's exactly what it is ... a rumor."

Tebow then says he has no plans to run for a political office ... at the moment ... but doesn't close the door on plans to get in the game somewhere down the line.

In fact, the rest of his video sounds like a political speech!!!